The subject matter described herein relates generally to wind turbines and, more particularly, to methods and systems for providing a variable mechanical brake torque to brake discs of wind turbines.
Wind turbines have been receiving increased attention for being environmentally safe and relatively inexpensive alternative energy sources. With the growing interest in alternative energy sources, considerable efforts have been made to develop wind turbines that are reliable and efficient.
At least some wind turbines include a plurality of rotor blades coupled to a drivetrain via a rotor. Some drivetrains include a gearbox that facilitates increasing and/or decreasing a torque of the rotor. Some gearboxes include a brake system that facilitates reducing a speed of the rotor. More specifically, a brake caliper applies a force against at least one side of a brake disc, which is coupled to the rotor, creating friction and causing the brake disc to slow and/or stop. A brake torque, which represents a power of the brake system, may be calculated by multiplying the force applied by the brake caliper by a distance from the point of applied force to a hub center.
At least some known mechanical brake systems are capable of applying only one high constant brake torque onto the brake disc. Repeated and/or extended applications of a high constant brake torque may damage the rotor and/or the gearbox, ultimately influencing a reliability of the rotor, the gearbox, and/or the drivetrain.